This invention relates in general to clutches and more particularly to a clutch that permits relative rotation in only one direction.
Some machines contain shafts which must rotate in only one direction, while others have shafts which may only overrun other shafts. In either case some type of clutch is required to, in effect, allow relative rotation between the shafts in only one direction. Indeed, in the opposite direction of rotation the clutch must have the capacity to transfer torque from one shaft to another.
The typical one-way or unidirectional clutch contains locking elements which lie in pockets located between two shafts. In one direction of relative rotation, the elements float in the pockets and do not impede the relative rotation. Hence, the one shaft will rotate relative to or overrun the other shaft. In the other direction the elements lodge between converging surfaces, which form the pockets, and transmit torque from the one shaft to the other. Usually springs urge the rolling elements lightly against the converging surfaces so that when a reversal in direction occurs, the shafts immediately lock up to transfer torque. The locking elements are usually balls or rollers and almost always rollers when the torque is high, with the length of the rollers to a large measure depending on the magnitude of the torque. But rollers, particularly long ones, tend to skew between the converging surfaces at the pockets, and for this reason are often confined in cages. Cages add to the complexity and cost of the clutches.
The present invention resides in a unidirectional clutch which contains elongated rollers to transmit torque, yet does not rely on a cage to prevent the rollers from skewing. The clutch is quite compact and easy to manufacture.